jsp相关简单应用

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DAO:

package DAO;


public class dao {
	public static java.sql.Connection getconn(){
		try {
			Class.forName("com.mysql.jdbc.Driver");
			String jdurl = ("jdbc:mysql://localhost:3306/exa");
			java.sql.Connection conn = java.sql.DriverManager.getConnection(jdurl, "root", "93694264");
			System.out.println("数据库连接成功");
			return conn;
		} catch (Exception e) {
			System.out.println("数据库连接失败");
			e.printStackTrace();
		}
		return null;
	}
	
	public static void insert(int id,String name){
		java.sql.Connection conn = getconn();
		String sqlinsert = "insert into exa(id,name) values(?,?);";
		java.sql.PreparedStatement pst = null;
		try{
			pst = conn.prepareStatement(sqlinsert);
			pst.setInt(1, id);
			pst.setString(2,name);
			pst.executeUpdate();
		}catch(Exception e){
			e.printStackTrace();
		}
	}
	
	public static void delete(int id) throws Exception{
		java.sql.Connection conn = getconn();
		conn.setAutoCommit(false);
		String sqldelete = "delete from exa where id = "+id;
		try{
			java.sql.Statement st = conn.createStatement();
			st.execute(sqldelete);
			conn.commit();
			}catch(Exception e){
			e.printStackTrace();
		}
	}
	
	public static void update(int id,String name){
		java.sql.Connection conn = getconn();
		String sqlupdate = "update exa set name = ? where id = ?;";
		java.sql.PreparedStatement pst = null;
		try{
			pst = conn.prepareStatement(sqlupdate);
			pst.setString(1,name);
			pst.setInt(2, id);
			pst.executeUpdate();
		}catch(Exception e){
			e.printStackTrace();
		}
	}
	
}



index:

<%@page import="DAO.*"%>
<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>



  
    
    
    
	
	
	    
	
	
	
  
  
  
  <%
  	Connection conn = dao.getconn();
  	String sql = "select * from exa;";
  	ResultSet rs = null;
  	Statement st = null;
  	try{
  		st = conn.createStatement();
  		rs = st.executeQuery(sql);
  	}catch(Exception e){
  		e.printStackTrace();
  	}
   %>
  总表：
  	
  		<%
  			while(rs.next()){
  			Mess mess = new Mess();
  			mess.setId(rs.getInt(1));
  			mess.setName(rs.getString(2));
  		 %>
  		 
  		 <%
  		 	}
  		 	rs.close();
  		 	st.close();
  		 	conn.close();
  		  %>
  	

  		

  			
id
  			
name
  			
操作
  		

  		 	
<%=mess.getId() %>
  		 	
<%=mess.getName() %>
  		 	
删除
  		 
添加信息：

  	

  		

  			
id
  			
name
  			
操作
  		
  		

  			

  			

  			

  		
  	

修改信息：

  	

  		

  			
id
  			
name
  			
操作
  		
  		

  			

  			

  			

  		
  	

  


servlet:
package Myservlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import DAO.dao;

public class serv_Servlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public serv_Servlet() {
		super();
	}

	/**
	 * The doGet method of the servlet. 

	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		String sid = request.getParameter("id");
		String name = request.getParameter("name");
		String action = request.getParameter("action");
		int id = Integer.parseInt(sid);
		if(action.equals("login")){
			if(id==1&name.equals("123456")){
				response.sendRedirect("index.jsp");
				
			}
		}else if(action.equals("add")){
			try{
				dao.insert(id, name);
				response.sendRedirect("index.jsp");
			}catch(Exception e){
				e.printStackTrace();
			}
		}else if(action.equals("change")){
			try{
				dao.update(id, name);
				response.sendRedirect("index.jsp");
			}catch(Exception e){ 
				e.printStackTrace();
			}
		}else if(action.equals("delete")){
			try {
				dao.delete(id);
				response.sendRedirect("index.jsp");
			} catch (Exception e) {
				e.printStackTrace();
			}
		}else{
			System.out.println("error!!");
		}
		
	}

	/**
	 * The doPost method of the servlet. 

	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		out.println("");
		out.println("");
		out.println("  ");
		out.println("  ");
		out.print("    This is ");
		out.print(this.getClass());
		out.println(", using the POST method");
		out.println("  ");
		out.println("");
		out.flush();
		out.close();
	}

}



login:
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>



  
    
    
    
    
	
	
	    
	
	
	

  
  
  
  

    

    	

    		
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